This specification relates to information retrieval.
The Internet provides access to a wide variety of resources, such as image files, audio files, video files, and web pages. A search system can identify resources in response to queries. The search system ranks the resources and provides search results that link to the identified resources. The search results are typically ordered for viewing according to the rank.
Some search systems rank each resource based, in part, on a number of other resources that include a link to the resource. For example, a resource that has a large number of resources that link to the resource may be ranked higher than another resource that has a smaller number of linking resources. However, some resources may be linked to by a number of resources that is disproportionate compared to the amount of traffic the resource receives from theses links.